Final answer:
Drinking alcohol and smoking cigarettes during pregnancy can have harmful effects on the developing baby, including abnormalities in growth and development, premature birth, low birth weight, stillbirth, and SIDS. It can also increase the risk of miscarriage and infertility.
Step-by-step explanation:
It is dangerous for a pregnant woman to drink alcohol or smoke cigarettes because these substances can have harmful effects on the developing baby. When a pregnant woman drinks alcohol, it can cross the placenta and enter the baby's bloodstream, causing abnormalities in growth and development. Smoking during pregnancy can result in premature birth, low birth weight, stillbirth, and sudden infant death syndrome (SIDS). It can also increase the risk of miscarriage and infertility.